1. Field of the Invention
The present invention relates to a circuit design of a light emitting diode lamp tube, and in particular refers to a light emitting diode lamp tube compatible to a T5/T8 electronic ballast and capable of completely activating the intelligent LED lamp tube and reducing light-up time, attaining effects of low power consumption, high adaptiveness and energy conservation.
2. Description of the Related Art
Conventionally, T5 or T8 fluorescent lamps are extensively applied to illumination occasions for energy conservation and high power factor. However, with the rapid development of light emitting diode (LED) lamp tube products, T5 or T8 filament heating discharge lamp tubes are gradually replaced. In view of this, a LED lamp tube compatible to a T5/T8 electronic ballast is therefore developed by operators. FIG. 1 is a circuit block diagram of a conventional LED lamp tube compatible to a T5/T8 electronic ballast. In FIG. 1, a lamp holder 1 is disposed with an electronic ballast and a LED lamp tube 3 compatible to the electronic ballast 2, in which the LED lamp tube 3 is activated by the electronic ballast 2.
Generally, the electronic ballast 2 can have two classifications, a self-oscillating electronic ballast and an IC-controlled electronic ballast. When the LED lamp tube 3 is connectively conducted to the IC-controlled electronic ballast, an integrated circuit (IC) adopted by the IC-controlled electronic ballast can be utilized to control a control circuit, capable of providing effects of high power factor, low harmonic distortion, high efficiency. FIG. 2 is an equivalent-circuit diagram of a conventional self-oscillating electronic ballast. In FIG. 2, it can be appreciated that resonance of an inductor/capacitor circuit and properties of inductor transformer applied by the self-oscillating electronic ballast is utilized for circuitry control. When the LED lamp tube 3 is connectively conducted to the self-oscillating electronic ballast, a startup frequency and a working frequency of the self-oscillating electronic ballast are discordant due to large diversities of voltage, electrical current and fluorescent lamp tube, and problems of an output current larger than an lamp tube rating current in the electronic ballast, increased power consumption and energy consumption, rapidly-increased temperature rise are therefore derived, resulting in affecting an lamp string of the LED lamp tube 3 and other electrical component and damage of the LED lamp tube 3 and internal system. It can be appreciated that, variation problems of the electronic ballast 2 cannot be determined during the startup period or usage period in the conventional LED lamp tube compatible to the T5/T8 electronic ballast. Accordingly, the inventor provides a light emitting diode lamp tube compatible to a T5/T8 electronic ballast to improve defects of the conventional LED lamp tube compatible to the T5/T8 electronic ballast.